Properties properties = new Properties();
properties.setProperty("jclouds.filesystem.basedir", "/tmp/blobstore");
BlobStoreContext context = ContextBuilder
        .newBuilder("filesystem-nio2")
        .credentials("identity", "credential")
        .overrides(properties)
        .build(BlobStoreContext.class);
S3Proxy s3Proxy = S3Proxy.builder()
        .blobStore(context.getBlobStore())
        .endpoint(URI.create("https://127.0.0.1:8080"))
        .build();
s3Proxy.start();
while (!s3Proxy.getState().equals(AbstractLifeCycle.STARTED)) {
    Thread.sleep(1);
}

@Rule
public S3ProxyRule s3Proxy = S3ProxyRule.builder()
                   .withCredentials("access", "secret")
                   .build();
@Test
public void example() {
    //set up an AWS S3 client using the rule as an endpoint
    AmazonS3 s3Client = AmazonS3ClientBuilder
            .standard()
            .withCredentials(
              new AWSStaticCredentialsProvider(
                new BasicAWSCredentials(s3Proxy.getAccessKey(), 
                                        s3Proxy.getSecretKey())))
            .withEndpointConfiguration(
              new AwsClientBuilder.EndpointConfiguration(s3Proxy.getUri().toString(), 
                                        Regions.US_EAST_1.getName()))
            .build();
    s3Client.createBucket("test_bucket");
    
    //exercise your code that you want to test, using the above client
    myS3Uploader.uploadFile(s3Client, someFile);
    //verify the expected results of the above code
    List<S3ObjectSummary> summaries = s3Client.listObjects("test_bucket")
                                      .getObjectSummaries();
    assertThat(summaries).hasSize(1);
    assertThat(summaries.get(0).getSize()).isEqualTo(someFile.length());
}